It is known to preserve live fish for bait by aerating the storage water in a tank. See, for example, U.S. Pat. No. 4,146,989 issued Apr. 3, 1979 to Vanus, et al. for BAIT TANK, U.S. Pat. No. 4,168,590 issued Sept. 25, 1979 to Beshoner for LIVE BAIT SUPPORT APPARATUS, and U.S. Pat. No. 4,677,785 issued July 7, 1987 to Lambourn for AERATED LIVE BAIT BUCKET.
Except for Beshoner, all of the aerated bait containers in the known prior art use an external source of air or water for aerating the storage water. Beshoner recirculate the water within the tank and aerates the water by spraying the return water on the surface of the storage water. The spraying of the water into the storage water creates undesirable turbulence and bubbles in the storage water. The bubbles sometimes accumulate on the gill rakers of the bait fish, causing asphyxiation.
Other patents for bait tanks show the cooling of water to preserve the fish, including U.S. Pat. No. 2,555,128 issued May 29, 1951 to Gutshall for FISHING CREEL COOLED BY EVAPORATION OF WATER, U.S. Pat. No. 2,631,402 issued Mar. 17, 1953 to Lastofka for REFRIGERATED BAIT BOX, U.S. Pat. No. 2,935,858 issued May 10, 1960 to Kingery for FISH BAIT CONTAINERS, and U.S. Pat. No. 4,697,380 issued Oct. 6, 1987 to Fenske for BAIT CONTAINER.
Other than Gutshall, the known prior art refrigerated bait tanks use ice as the refrigerant. Gutshall passively evaporates water from the outer surface of a water-permeable absorbent material maintained in close proximity to an inner water-impermeable heat conductive liner that holds the storage water.